UNUSUAL NANOMETER-SIZED NSUTITE FROM BASIC SYSTEMS
作者单位：Department of Chemistry Institute of Materials Science University of Connecticut Starrs Connecticut 06269-4060 North Atlantic Group Duracell Company 37 A Street Needham Massachusetts 02194-2875
会议名称：《第二届中日化工学术研讨会》
会议日期：2002年
学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学]
关 键 词：nanometer-sized nsutite basic systems defects
摘 要：Nanometer-sized manganese oxides materials are one of the focuses for scientists in this field and novel properties may be found, due to quantum confinement effects. The most widely used cathode materials in primary alkaline batteries nsutite (γ-MnO2) is often described as an intergrowth of pyrolusite and ramsdellite tunnel structures. Our research concerns the preparation, structures, and properties of nanometer-sized nsutite with the longest diameter sizes of about 30-40 nm from basic systems, instead of traditional nsutite synthesized in the acidic environments. Flat perfect crystal surfaces of nanometer-sized nsutite characterized by FESEM show that there are pure and fewer cation vacancies et al defects on the surface of the frameworks, further proved by IR, TG, and BET methods. CV experiment results showed that the currents at -240 mV, corresponding to the homogeneous reduction from Mn4+ to Mn3+ , were twice of traditional samples from acidic environments, due to the small particle size, fewer cation vacancies, and larger numbers of Mn4+ ions on the surfaces.